Fuel with audio and visual effects

ABSTRACT

A fuel for producing attractive audio and visual burning results is disclosed. The drawings should be amended as follows:  
     FIG.  1:  On the lefthand side, number  12  is changed to  17;    
     FIG.  7  Add numbers and lead lines  65 A and  65 B  
     FIG.  7 A: Add numbers and lead lines  32   a,    33   a,    66   a,    66   b,    37  and  39    
     FIG.  10:  Change “ 66 ” to — 66   a—   
     FIG. C: Change “C” to — 10 C—; change “ 90 ” to — 94—   
     FIG.  11:  Add — 68 — and lead line  
     FIG.  13:  Change the two numbers  66  and  66   b  and  66   a  as shown; add the numbers  65 A and  65 B; add the numbers  83  and  84  and lead lines  
     FIG.  14:  Add the numbers  1, 2, 3, 4,  and  5  with lead lines

BACKGROUND OF THE INVENTION

[0001] This invention relates to a free standing fireplace hearth and afuel composition for use therein.

[0002] In many patio, deck, back yard or other similar outside settings,an actively burning fire is often used to add significant ambiance tothe setting. In addition to the visual appearance of the fire, thesetting is enhanced by the soothing and pleasing crackling and poppingsound of a wood burning fire. However, wood burning fires of this typeoften require significant attention to periodically add logs to maintainthe fire. Wood burning fires generate a significant amount of ash, sootand the like thereby requiring clean up. Further, open kettles or thelike which are commonly used to house the burning logs present asignificant hazard and often do not adequately contain the fire duringuse thereby leading to the potential and dangerous spread of the firethrough falling and burning logs, cinders or the like. Constantattention to the fire is thereby prudently required.

[0003] Therefore, there is a need for an improved outdoor fireplace orhearth which avoids these above-described drawbacks while still offeringthe visual and audible ambiance of a burning wood fire.

[0004] In a further aspect of the invention, it is highly desirable toprovide a self-containing fire hearth which provides the ambience of awood burning fire, that is a flame which has the appearance and sound ofa wood burning flame, but without the necessity of wood fuel or cleanupof waste combustion products usually attendant a wood-fueled fire.Moreover and in this regard, it will be appreciated that an “ambience”fire or flame need not be measured by the typical parameters applied toa fire. For example, heat output, or BTUs, is a typical fire or heatperformance criteria as is the heat producing efficiency from the fuelused. In a free-standing fire or hearth for ambience purposes, theseparameters and efficiencies are relatively unimportant. In the case ofheat production, the less heat produced, the better.

[0005] What is important are entirely different characteristics, namelyburn time, fuel volume and burn characteristics. Thus, the efficiency ofa decorative or ambient fire, for example, is measured in considerationof these parameters and their coalescence to provide the most desirableaesthetic result, with an acceptable burn time, at the least operationalcost.

[0006] For example, acceptable burn characteristics require a fire withgolden colored flame having random dancing patterns. A desirable burntime per fuel load is in the two to four hour range and the fuel costper unit used should be low, compared to other systems within the aboveparameters.

[0007] Accordingly, it is a further objective of the invention toprovide a freestanding fireplace hearth with an improved efficiencytaking into account burn characteristics, volume of fuel used and burntime or duration per fuel unit consumed.

[0008] A further objective of the invention has thus been to provide afreestanding fireplace hearth with improved flame color and burningsound like a wood burning fire, at acceptable burn time and fuel volumeused.

SUMMARY OF THE INVENTION

[0009] This invention overcomes the above-described and other drawbacksof known fireplace or hearth systems while still offering a visually andaudibly pleasing safe live fire and associated ambiance in an outdoorsetting.

[0010] In a presently preferred embodiment, the invention includes afree standing fireplace hearth for burning a fuel to provide anattractive ambiance fire in an outdoor setting. The fireplace hearthincludes a base having a fuel tray defining a chamber slidably mountedtherein on a drawer-like structure for movement between open and closedconfigurations and a spring biased latch to releasably secure the trayin the closed configuration. The tray is configured with a throat as anintegral part of the overall combustion system as will be described. Asnuffer or burner is disposed in the hearth over the tray and providesflaps or dampers for controlling the flame height and for snuffing outthe flame as desired. The tray is mounted for movement on the drawerstructure between a lowered and a raised position. A plurality of camsare pivotally oriented with respect to the tray. A stop is mounted onthe base relative to the tray so that as the tray approaches the closedconfiguration, the tray abuts against the stop. Continued movement ofdrawer rails on which the tray is mounted toward the closedconfiguration activates the cams and thereby elevates the tray relativeto the snuffer into the raised position and in operative contact withthe snuffer.

[0011] A log set of fiber/ceramic or other wood simulation material isoperably disposed over the snuffer. Flame from the snuffer dances upthrough passages in the log set which has features which glow. Airmoving up the passages produces lift to enhance the burn characteristicsof the flames.

[0012] A pair of spaced dampers or shutters are mounted for movement toand between a closed snuffing configuration and a fully open burnconfiguration. Each of the damper shutters are coupled via a linkage toa rotational control knob such that rotation of the control knob in afirst direction pivots the damper shutters toward the closed snuffingconfiguration to extinguish the burning fuel. Rotation of the controlknob in a second opposite direction pivots the damper shutters towardthe fully open configuration to increase the flame height through thelog set.

[0013] A plurality of posts extend upwardly from the base to support aroof. The roof includes a heat shield mounted on the interior thereof todeflect hot air generated by the burning fuel from impinging upon theroof and thereby maintains the roof at a lower temperature than the heatshield during fuel burning. At least a portion of the heat shield isspaced from the roof to define space for an insulation layer of airbetween the heat shield and the cover. A plurality of baffles areincluded on the heat shield to direct the heat out from under the roof,off of the heat shield and cooler air into the insulation layer of airbetween the roof and the heat shield.

[0014] The present invention in another aspect includes a specificcomposition of fuel which is suitable for use in the free standingfireplace hearth. The fuel in a presently preferred embodiment is a gelcomposition which satisfies the characteristics of fireplace fuel withrespect to aesthetic features such as producing golden high luminousflame without producing an offensive odor or smoke while stillgenerating a crackle and pop sound. Further, the fuel is safe forhandling and storage purposes and the formulation is of generallynon-toxic components as well as being self-contained if spilled,environmentally safe in burning, producing minimal pollutants and beingreadily extinguishable without any smoke buildup. Further, the burntfuel does not produce any significant amount of residue or the like.

[0015] Accordingly, it will be appreciated that the fuel tray, the fuelchamber throat in the tray, the snuffer with its dampers and the log setcombine to define a combustion system producing a flame having therandom pattern appearance of a wood flame with desirable burn time andlow fuel volume requirements.

[0016] In brief, the combustion system performs or acts something like acarbueration system.

[0017] When the drawer is shut the fuel chamber mates or couples withthe snuffer assembly to complete the combustion system and also acts asa way to extinguish the flame. Air is mixed with the fuel. The fuelvaporizes in the fuel chamber and the air-alcohol gas mixture rises ormoves through the throat out of the chamber via a plurality of flamepaths created by a wedge-shaped, diverter of the snuffer and theopenings on top of the snuffer assembly. The damper or doors control theheight of the flames and also act when closed to snuff out the flame.The log set is decorative. As the flames move through the log set, theyactually warm the log set material causing it to glow when touched byflame. The flames move through the log set with as little impingement aspossible so that sooting is kept to a minimum. The passages in the logset warm up and cause convection of additional ambient air up throughthe passages so the fire or flame is decoupled and is lifted uptherethrough. The system is self-regulating, so as the user adjusts thedampers, increasing or decreasing the size of the flame, the combustionsystem continues to work the same way.

[0018] A preferred fuel according to the invention is a gel composition,or mix of a lower alkyl alcohol, water, flammable organic tertiary butylalcohol and double or single walled microencapsulated solvents, gellingagent, polyacrylic acid, cross linking agent and surfactant. Such a fuelas described herein, when used in the hearth described herein, producesdesirable burn characteristics over an acceptable burn time and with anacceptable fuel volume required.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The objectives and features of the invention will become morereadily apparent from the following detailed description taken inconjunction with the accompanying drawings in which:

[0020]FIG. 1 is a perspective view of the invention showing in phantom awithdrawn fuel tray for fueling;

[0021]FIG. 2 is a front elevational view of the invention of FIG. 1;

[0022]FIG. 3 is a side elevational view of the invention of FIG. 1;

[0023]FIG. 4 is a rear elevational view of the invention of FIG. 1;

[0024]FIG. 5 is a plan view of the invention of FIG. 1;

[0025]FIG. 6 is a bottom view of the invention of FIG. 1;

[0026]FIG. 7 is a cross-sectional view taken along lines 7-7 of FIG. 1showing the fuel tray in closed, operational position;

[0027]FIG. 7A is a view of the fuel tray and its drawer mount similar toFIG. 7, but showing only the tray, drawer components and snuffer inlowered partially opened position;

[0028]FIG. 8 is a cross sectional view taken along lines 8-8 of FIG. 7with certain components removed for clarity;

[0029]FIG. 9 is a cross sectional view taken along lines 9-9 of FIG. 7Awith certain components removed for clarity;

[0030]FIG. 10 is a perspective view showing the tray, drawer componentsand snuffer of FIGS. 1, 7A and 9;

[0031]FIG. 10A is a perspective view of the upperside of the fuel trayand drawer of the invention,

[0032]FIG. 10B is a perspective view of the underside of the hearthshowing fuel tray and drawer components of the invention;

[0033]FIG. 10C is a perspective view of the forward end of the fuel trayand drawer of the invention viewed from a rear perspective;

[0034]FIG. 11 is a perspective view of the roof and heat shield of FIGS.1-7;

[0035]FIG. 12 is a perspective view of a corner structure of theinvention as shown in FIG. 1;

[0036]FIG. 13 is a diagrammatic elevational illustration of thecombustion systems of the invention of FIG. 1; and

[0037]FIG. 14 is a diagrammatic perspective illustrative of a log setused in the hearth of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0038] Referring to the figures, presently preferred embodiments of afree standing fireplace hearth 10 according to this invention are shown.The hearth 10 is intended for outdoor use and is free standing andportable as needed.

[0039] The hearth 10 includes a base 12 with four downwardly projectinglegs 14, each of which include a rotationally adjustable foot 16, all ofwhich in combination could be used to level the base 12 and the hearth10 as appropriate. An upwardly extending post or column 18 is mountedproximate each corner of the base 12 and the posts 18 in combinationsupport a roof 20. The roof 20 includes a centrally located vent cap 22secured to and spaced from the roof 20 to provide for the free flow ofair therebetween. A support arch 24 is mounted between each pair ofadjacent posts 18. A plurality of preferably artificial, althoughrealistic appearing, logs making up log set 26 (FIGS. 13, 14) arepositioned atop the base 12 within the hearth 10. Log set 26 includesside logs 27, 29 and a center log 31, for example.

[0040] It will be appreciated that posts 18 are preferably formed,hollow columns having in two adjacent sides slots 19 and 21 (FIG. 12).Also, each slot is provided with a groove 23 in a bottom of the slot andextending a short distance downwardly.

[0041] On assembly, the corner posts 18 are secured in appropriaterecesses in base 12. A resilient tube, gasket or bumper is inserted intoa lower end of slot 19, 21 to resiliently support a preferablytransparent panel 17, such as glass or plastic slid downwardly to thebumper in the slots so the bottom edge of panels 17 are spaced from base12. Thereafter, a tenon end 25 of a support arch 24 is slid into grooves23 to lock the arches 24 in place and columns 18 together, the bottom ofgrooves 23 supporting the arches 24 above the glass panels 17 in slots18, 21.

[0042] The roof 20 is provided with corner projections 15 (FIGS. 11, 12)which then fit into the top ends of corner columns 18 for securing theroof 20 and heat shield 68 thereon.

[0043] It will be appreciated that hearth 10 includes a floor 13extending across the base 12 and alongside snuffer 42. Floor 13 maycomprise two formed components of aluminum, metal, ceramic or othersuitable material on each side of snuffer 42. One suitable, but notnecessary material for the floor is a material manufactured by TheFoundry in Toronto, Canada, under the name “Cool Crete”.

[0044] A drawer structure 28 is slidably mounted in the base 12 formovement to and between a closed configuration (FIG. 9) and toward anopen configuration (FIG. 8). The drawer structure 28 is slidably mountedon rollers 38. Rear rollers 38 are mounted on drawer rails 44, 45 andforward rollers 38 (FIG. 10B) on stationary slide rails 55 a and 55 b.

[0045] A control knob 30 projects from the base 12 for adjusting dampers32, 33 to control flames resulting from burning fuel 34. Mounted withinthe drawer 28 is a fuel tray 36 defining a fuel chamber 37 for holdingthe vaporizing fuel 34. Tray 36 also defines a constricted throat 39tapering inwardly over chamber 37.

[0046] The tray 36 is movably mounted on the drawer structure 28 formovement to and between a lowered position (FIG. 7A) when the drawer ismoved toward an open configuration (FIGS. 7A and 8) and a raised orclosed position (FIGS. 7 and 9). In the raised position, spaceduppermost flanges or lips 40 of the tray 36 are placed into operativesealing engagement with lower flanges or lips 48 (FIG. 7) of a snuffer42 mounted within the base 12. The tray 36 in the raised sealingconfiguration inhibits air from entering between the lips 40 and flanges48 during operation of the hearth 10 and allows extinguishment of thefire when desired by operation of the snuffer dampers 32, 33.

[0047] The tray 36 is operatively coupled to the slidable drawer 28 byway of a cam mechanism comprising, for example, cam followers 49 mountedon tray 36 and cam slots S1 (FIGS. 8, 9) disposed in slidable drawerrails 44, 45 (FIG. 7A). As shown, cam followers 49 comprise a camfollower portion 49 a and an enlarged flange 49 b outwardly thereof(with respect to tray 36) to maintain the cam followers in the slots 51in the rails 44, 45.

[0048] When the drawer 28 is pushed inwardly or rearwardly, the back endof the tray 36 engages a stop 46. Continued rearward movement, however,of rails 44, 45 pushes the cam slots 51 under or across the followers49, raising them, and thus tray 36, upwardly toward snuffer 42, wherelips 40, 48 engage effectively to cut off air passages therebetween.

[0049] In an alternative embodiment (not shown) the tray 36 is coupledto the drawer 28 by a plurality of links which are pivotally coupled ata first lower end to the tray and at a second upper end to the drawer28. As the drawer slides or rolls from the open configuration toward theclosed configuration, a back end of the tray 36 approaches a stop 46(see FIG. 9) mounted on the base 12 so that as the drawer approaches theclosed configuration, the tray abuts against the stop. Continuedmovement of the drawer 28 toward the closed configuration thereby pivotsthe links 44 toward a more vertical orientation. Since the tray isprevented from translating in a generally horizontal direction, it risesvertically on the links into sealing engagement with the snuffer throughthe continued lateral movement of the drawer inwardly or rearwardlytowards the closed configuration.

[0050] Once the drawer 28 is in the closed configuration and the tray 36is in the raised position, the drawer 28 is maintained in the closedconfiguration by a spring biased latch 50 which engages holes 52 in akeeper plate 54 of the stationary slide rails 55 a, 55 b. To open thedrawer, a user grasps a catch or arm 56 on the latch 50 to thereby pivotthe latch out of engagement with the keeper plate 54 and permit thedrawer 28 to be pulled open and the tray 36 lowered as the cam followers49 descend in slots 51 when drawer 28 is pulled out so the tray is atleast partially exposed for filling.

[0051] As shown in the figures and particularly FIGS. 8 and 9, thecontrol knob 30 is mounted on a shaft 58 for pivotal movement to adjustthe position of spaced dampers 32, 33 of the snuffer 42. These aremounted for movement to and between a closed snuffing configuration anda fully open configuration (dotted line in FIG. 13), with intermediateburning positions adjusting the size of the respective openings in thesnuffer 42 and thus any flame height. Such control movement of dampers32, 33 is illustrated by arrows A, B in FIG. 7. The dampers 32, 33 arecoupled via a pivotable linkage 62 to the shaft 58 so that upon rotationof the shaft 58 by the control knob 30, an upper edge of the dampershutters moves into or out of engagement with an upper edge 65 a, 65 bof a V-shaped diverter 64 of snuffer 42 extending generally parallel tothe shaft. Similarly, rotation of the control knob and shaft moves alower edge 32 a, 33 a of each damper 32, 33 toward or away from a flange66 a, 66 b. In this regard, the damper could be pivoted. Preferably theyare slotted to receive pins 67 for motion as described. When the dampers32, 33 are engaged with the adjacent structure as described, in closedconfiguration, and fuel burning is thereby extinguished. Alternatively,adjustment of the position of the dampers 32, 33 controls the air flowto the flame for regulating the intensity and height thereof. Thedampers 32, 33, diverter 64, flanges 66 a, 66 b and related structurecombine to form a flue or controller for the burning fuel.

[0052] Of course, while specific drawer and motion compartments havebeen described, and other suitable components could be used, it will bereadily appreciated that a preferred embodiment of the inventioncomprises a fuel tray 36 which can easily be unlatched and drawnforwardly or outwardly of hearth 10 for loading of a gel fuel 34 (to bedescribed) or other suitable fuel.

[0053] Thereafter, the drawer 28 and tray 36 are pushed rearwardly intohearth 10 and the tray is lifted by the ending motion of the return tooperative engagement with a snuffer 42.

[0054] It will be appreciated that the lower flanges 48 of the snufferare engaged with upper flanges or lips 40 of the tray 36 to effectivelyseal the chamber 37 so the snuffer 42 is operable to extinguish flametherefrom when dampers 32, 33 are closed.

[0055] A projection 35 of knob 30 extends downwardly and blocks outwardmotion of drawer 28 and tray 36 unless the knob 30 is positioned toclose openings 60, 61 in a snuffer 42 with dampers 32, 33 (FIG. 8).Thus, for all operable open or “burn” positions of dampers 32, 33, knob30 and projection 35 block outward movement of drawer 28. This preventsthe opening or withdrawal of fuel tray 36 when any flame is burning.

[0056] Shaft 58 is engaged by a double spring clip 59 which frictionallymaintains the rotary position of shaft 58 and thus that of linkage 62and the damper position, once set.

[0057] It will be also be appreciated that stationary rails 55 a and 55b are secured to base 12. Rollers 38 are oriented on the rear ends ofdrawer rails 44, 45 and ride in the stationary rails 55 a and 55 b,respectively. Forward rollers are mounted on the stationary rails 55 aand 55 b and support the drawer rails 44, 45 so those rails are easilypulled and pushed outwardly and inwardly as described, carrying tray 36.Also, it will be appreciated that tray 36 moves with respect to drawerrails 44, 45 after the tray is stopped by stop 46, in order that it israised toward snuffer 42.

[0058] A strap 53 (FIG. 10B) is disposed to secure stationary rails 55a, 55 b from separating apart.

[0059] The roof 20 of the fireplace hearth 10 includes a single pieceheat shield 68 (FIGS. 7 and 11) mounted interiorly thereof to deflecthot air generated by the burning fuel from impinging upon the roof 20.This maintains the roof at a lower temperature to avoid someone beingburned by touching the roof 20 during operation of the fireplace hearth10. The heat shield 68 is spaced from the roof 20 to thereby provide aninsulation layer of air 70 between the heat shield and the roof 20 andfurther minimize the transfer of heat to the roof 20. Additionally,around the perimeter of the heat shield 68, a raised baffle 72 isprovided which terminates at the corners of the heat shield at slits 74defined by the space between edges 75 of roof 20 and 76 of heat shield68 (FIG. 7). A tongue 77 connects the heat shield 68 to the roof 20 ateach of the four corners. This structure allows for the hot air from thefire which impinges upon the heat shield to be directed outwardly anddownwardly away from the roof 20. Furthermore, the baffles 72 and slits74 between the roof 20 and the heat shield 68 allow for cooler air to bedrawn into and circulate around the roof 20, entering the space betweenthe heat shield and the roof 20 to provide the insulation of air 70therebetween. Furthermore, air which is warmed in the insulation layer70 rises and escapes between the cap 22 and the roof 20 and is replacedby cooler air drawn in by slits 74. It will be appreciated that thepassage from slits 74 to caps 22 are unobstructed, allowing a free flowof air between roof 20 and shield 68 with the only contact between themat the corners. This helps keep roof 20 from becoming too hot.

[0060] Log set 26 is diagrammatically illustrated in FIGS. 1, 13 and 14.It may be made of a fiber and ceramic material or any other suitablematerial for this use. The log set 26 may be formed in one piece or in aplurality of separate pieces, fitted or joined together to provide theappearance of authentic logs. FIGS. 13 and 14 illustrate side logs 27,29 and a center log 31, for example, for illustrative purposes only.

[0061] However formed, the log set has a plurality of passages. Two ofthese are illustrated at 79, 80 (FIG. 13). These passages haverespective entry ends 81, 82 and outlet ends 83, 84. Entry ends 81, 82are disposed proximate the openings 60, 61 in snuffer 42 for receivingflames therefrom, the flames extending upwardly through passages 79, 80to and through outlets 83, 84.

[0062] It will also be appreciated that inlets 81, 82 are disposed ororiented such that ambient air can be drawn into the inlets, mixing withthe flames, decoupling the flame, and lifting the flame up through thelog set 26. Further, it will be appreciated that the outer logs 27, 29could be lower than the center log 31. In any event, the top edges ofdampers 32, 33 form a gap (changing when the dampers are moved) betweenthe dampers and the logs 27, 29 respectively. This gap allows air intoinlets 81, 82 to decouple and lift the flames through passages 79, 80.

[0063] As the flame moves up passages 79, 80 they heat the surroundinglog set material and this heating produces a convection effect, drawingoutside air 85, 86 into the passages 79, 80 and into the flames. Theamount of heat so generated and the resulting convection effect producedis controlled by the flames which are in turn controlled by the positionof dampers 32, 33. The drawing in of decoupling air is thusself-regulating as a function of flame control by the dampers 32, 33,and as a function of the gap between top edges of the dampers and eitherthe logs or any adjacent floor structure.

[0064] While only two passages 79, 80 are shown in FIG. 13, there may benumerous passages through the log set 26, such as the passages 1-5 inFIG. 14. As shown, it is desirable that the passages are generallyoriented to reduce actual flame contact on the log set material andthereby reduce sooting of the surfaces. The manner of the formation ofthe log set 26 or of its individual components at this interconnectionis not a part of this invention. The passages such as 79, 80 can beformed through the log components or therebetween as desired.Preferably, there is an elongated space between the respective outer orside logs 27, 29 and center log 31. This space (passages 79, 80 forexample) are open at the bottom near snuffer 42, but may be bridged atthe top by contact of the side logs 27, 29 with the center log.

[0065] Having explained and described the structural features andoperation of the fireplace hearth according to presently preferredembodiments of this invention, the fuel 34 which is particularly adaptedfor use in the fireplace hearth comprises an additional aspect of thepresent invention. Specifically, the fuel for use in the presentinvention is a gel composition which satisfies the characteristics offireplace fuel with respect to aesthetic features such as producing agolden high luminous flame without producing an offensive odor or smokeand generating a crackle and pop sound. The fuel is safe for handlingand storage purposes and is formulated from generally non-toxiccomponents. The fuel is self-contained if spilled, environmentally safein burning, producing minimal pollutants and readily extinguishablewithout any smoke build-up. Further the product does not produce anysignificant amount of residue.

[0066] The gel composition for use in the present invention is a mixtureof a lower alkyl alcohol preferably ethanol, water, a flammable organiccomposition which produces a golden flame, such as an aliphatichydrocarbon preferably with an aniline point above 180° F. (such asodorless mineral spirits). Tertiary butyl alcohol also produces a yellowflame and stabilizes the gel. The gel composition also includescross-linked and double-walled microencapsulated solvents such astoluene, xylene, etc. and a gelling agent such as water and a minoramount of polyacrylic acid or polyacrylate, along with a cross-linkingagent and a surfactant. This is neutralized to a pH of 6-10 with a basicamine such as triethanolamine, diethanolamine, Ethomine (manufactured bySonobel) and other organic bases.

[0067] The gel formulation has a viscosity of 500,000 cps or higher in ahigh yield value fuel with excellent suspending properties. Thealiphatic hydrocarbons produce the golden yellow flame without producingsmoke or soot when burned unlike normal characteristics of aromaticcompounds.

[0068] A preferred formulation includes: Preferred Ingredients % byWeight % Range Ethanol anhydrous 58.5 50 to 65 proprietary Polyacrylicacid 0.5 0.2-1.2 (Carbopol E21 from BF Goodrich) Water 28.5 25-38Aliphatic hydrocarbons 6.84 2-15 (odorless mineral spirits) TertiaryButyl Alcohol 5.16 0-12 Denatonium Benzoate 40 ppm 40 ppm (bitteringagent, for safety) Triethanolamine 0.4 0.3-1.0 dye 5 ppm 2-30 ppmToluene/Xylene 0.1 0.1-1.0 capsules 100

[0069] The product is formulated by combining the polyacrylic acid withwater to wet the polyacrylic acid. The remaining components are addedinto the mix under agitation. The process is completed by neutralizingthe excess acid and further mixing for uniformity of the product bypumping (recirculation) of product through an in-line static mixer.

[0070] Preferably the solvent microcapsules are cross-linked anddouble-walled complexes formed by coacervation. Single walled complexescould be used. The cross linked gelatin double wall forms about 30% ofthe capsule weight. This prevents permeation of the solvents to providea long shelf life. Further, the capsules should have a size greater than500 microns, preferably 600 to 1500 microns with 50% or more of thecapsules being 900-1200 microns.

[0071] Further the solvent in the microcapsule is an aromatic solventpreferably a lower alkyl aromatic solvent such as toluene or xylenehaving a vapor pressure of 5 to 15 millimeters mercury at 68° F. and aboiling range of 300-325° F. This produces the best crackling soundduring burning.

[0072] This formulation is readily soluble in water making it easy toclean without leaving any stain on the carpet or flooring materials.Further the product is made safe to handle.

[0073] In an alternative embodiment of the fuel, the tertiary butylalcohol (TBA) is omitted and the aliphatic hydrocarbon (odorless mineralspirits) is increased to about 12% by weight. This aids in reduction ofthe flame point temperature of the fuel when that might be desired, butmay exhibit a small problem of separation of some of the components.

[0074] Turning now to FIGS. 13 and 14, the preferred combustion processprovided by the invention produces a flame with a random dancingpattern, of golden color as if burning from wood fuel, a cracklingauthentic wood burning sound, with minimal use of fuel and over a burntime of about 2-4 hours, depending on the position of dampers 32, 33.

[0075] Initially, a load or unit of fuel 34 is introduced to tray 36. Anamount of about 64 ounces of fuel 34 is appropriate to fill tray 36,pulled out from base 12, to a level as illustrated in FIG. 13.Thereafter, the drawer 28 and tray 36 are pushed into the hearth 10. Thelateral motion of tray 36 is stopped while slides or rails 44, 45continue rearwardly, as previously described. This cams the tray 6 upinto operative engagement with the snuffer 42 and the drawer 28 10 andtray 36 are latched in this position.

[0076] Knob 30 can now be turned to open dampers 32, 33. Vaporization offuel 34 occurs and the fuel vapor rises from tray 36 up through itsthroat 39 where it is constricted toward snuffer 42. The vapors arediverted by diverter 64 through openings 60, 61 between the diverter 64and dampers 32, 33.

[0077] When the vapors are lit by a suitable ignitor, flame is produced.This flame appears at the snuffer and rises upwardly toward passages 79,80. As the log set 26 heats, the heat draws air (85, 86) into the entryends of the passages 81, 82 between the dampers 32, 33 and the logs orany adjacent floor 13 (not shown) which may be situated just to the sideand beneath the logs. This convection air decouples the flame from thesnuffer 42 and tray 36 and helps lift the flame upwardly through andabove log set 26.

[0078] At the same time, air 87, 88 is drawn or convected upwardlyaround tray 36, cooling the tray and keeping fuel from becoming too hotand thus regulating its vaporization.

[0079] Dampers 32, 33 can be moved through manipulation of knob 30,turning shaft 58 and moving linkage 62 through various burn positionsregulating the flame produced. Movement of dampers 32, 33 to restrictopenings 60, 61 reduces the flame height and movement of dampers 32, 33to enlarge openings 60, 61, permitting passage of more fuel vapor,enlarging the flames and opening the side passages between dampers andlogs on floors for more decoupling air.

[0080] For all positions of knob 30 wherein dampers 32, 33 are open,knob projection 35 restricts outward lateral motion of tray 36 anddrawer 28 so that it cannot be extended out of hearth 10 while fuel isburning. When knob 30 is turned to move dampers 32, 33 to close offopenings 60, 61 and snuff out any flame, projection 35 is moved awayfrom its tray and drawer blocking position. This allows refueling.

[0081] When the dampers 32, 33 are moved to fully open openings 60, 61,maximum flame height and a shorter burn time of about two hours results.When dampers 32, 33 are moved to restrict openings 60, 61 to the lowestsuitable flame, an extended burn time of about four hours is provided bythe 64 ounce fuel unit.

[0082] This combustion system thus operates like a carbureation system,wherein the fuel vapors are concentrated by throat 39, throttled atdampers 32, 33 and then boosted, in flame, by the decoupling air.

[0083] While not restricted to any particular sizes, one combination ofsizes of various components found suitable is as follows. Of course,these dimensions are approximations for purposes of clarity ofdescription and may be varied in production.

[0084] Fuel tray 36 is about 12 inches long measured between two 10 trayend panels about 4⅝ inches wide at its bottom. Sides 89, 90 of tray 36extend up from bottom 91 and outwardly at an angle from the horizontalof about 100 degrees, for about 1½ inch. Throat panels 92, 93 then taperinwardly from upper edges of side 89, 90 for about 1 inch at an angle ofabout 35 degrees from the horizontal. From the inner edges of throatpanels 92, 93, the throat panels 94, 95 extend upwardly and outwardlyfor about 1½ inches at an angle of about 5 degrees from the vertical tothe tray lip or flange 40. Overall vertical height of the tray 36 frombottom 91 to flanges 40 is about 3½ inches. The throat 39 at the top ofthe panels 92, 93 is a little over 3 inches wide. When filled with apreferred unit of fuel 34, the filled fuel level is just below thejunction of panels 89, 90 with throat panels 92, 93 respectively.

[0085] The snuffer 42, at its opening to tray 36 through throat 39 isabout 12 inches long and that snuffer opening is preferably slightlylarger than the upper opening of the throat 39 between the upper edgesof panels 94, 95. The openings 60, 61 in snuffer 42 are about 12 incheslong and a little over one inch wide, resulting in a cross-sectionalarea of about 13 square inches for each opening 60, 61.

[0086] As noted, there are preferably numerous passages, such aspassages 79, 80 up through log set 26. Fire passages 1-5 are shown inFIG. 14. These passages are positioned in the log set to give theaesthetic appearance of an authentic wood fire by means of bridges overthe logs. At the bottom of the passages 1-5 (i.e. such as 78, 80) theentry openings 81, 82 defining a restrictive log out-take (81, 82) areabout 12 inches long and about ½ inches wide. The logs themselves areabout 16 inches long. Thus, the restrictive log take out flow area isabout 6 square inches on each side (FIG. 13). The air gap associatedwith these openings 81, 82 is formed by the dampers 32, 33 at their topedges and the logs or adjacent floor panels 13. This gap is betweenabout ¼ inches and ⅝ inches so that the effective decoupling airopenings are about 12 inches long and vary from ¼ to ⅝ inches wide.

[0087] These dimensions result in a combustion system which isself-regulating when the dampers are moved for the best efficiency forall burn positions. Of course, other dimensions, shapes and sizes of allcomponents will be appreciated. Variations in the parameters of onecombustion system component will or may vary the parameter of anothercomponent.

[0088] From the above disclosure of the general principles of thepresent invention and the preceding detailed description of at least onepreferred embodiment, those skilled in the art will readily comprehendthe various modifications to which this invention is susceptible.Therefore, we desire to be limited only by the scope of the followingclaims and equivalents thereof.

We claim:
 1. A fireplace hearth apparatus for producing a flame andcomprising a snuffer; a fuel tray oriented beneath said snuffer; saidfuel tray being movably mounted to said apparatus for downward andlateral movement for filling and said fuel tray being laterally movableunder said burner element and upwardly for operative engagement withsaid burner member.
 2. Apparatus as In claim 1 wherein said fuel tray ismounted for movement downwardly and away from said snuffer when saidtray is moved laterally from beneath said snuffer.
 3. Apparatus as inclaim 2 wherein said snuffer comprises at least one damper for closingoff flame burning from fuel in said fuel tray.
 4. Apparatus as in claim3 wherein said snuffer includes two elongated openings disposedgenerally vertically and a movable damper disposed at each opening foradjustably covering or opening said openings.
 5. Apparatus as in claim 4wherein said dampers are mounted for simultaneous movement selectivelytoward and away from the respective openings.
 6. Apparatus as in claim 3wherein said snuffer includes a lower opening and said fuel trayincludes an upper opening, said two openings being operably juxtaposedtogether when said fuel tray is disposed under and moved upwardly intoengagement with said snuffer.
 7. Apparatus as in claim 1 wherein saidtray is mounted on elongated first rails secured to said hearth forlateral movement with respect to said hearth and further including trayrails on each side of said tray, a first cam member on said tray railsand a second cooperating cam member on said fuel tray in operativerelation with said tray rails, such that said fuel tray is lifted andlowered as it moves respectively into engagement with and under saidsnuffer and out of engagement and laterally away from said snuffer. 8.Apparatus as in claim 7 wherein said first cam member is a cam slot andsaid second cam member on said fuel tray is a cam follower.
 9. Apparatusas in claim 1 including a releasable latch for holding said tray inoperative engagement with said snuffer.
 10. Apparatus as in claim 1further including an adjustable damper element operably disposed withrespect to said snuffer for controlling said flame, a knob mounted onsaid apparatus for adjusting said damper element between a flameshut-off position and a plurality of flame burning positions, and saidknob having a projecting portion which is positioned to block lateralmovement of said fuel tray from beneath said snuffer for all flameburning positions of said damper element.
 11. A fireplace hearthincluding a roof disposed over a fire area, said roof comprising: anupper roof panel; a heat shield under said roof panel; said heat shielddefining an air flow space between said roof panel and said heat shield;elongated openings defined by adjacent edges of said roof panel and saidheat shield for ingress of ambient air; a vent disposed in said roofpanel; and the space between said heat shield and said roof panel beingunobstructed, such that air freely flows from said elongated edges tosaid vent without obstruction in said flow.
 12. A hearth as in claim 11wherein said roof panel has a plurality of corners and said heat shieldis connected to said roof panel only at said corners.
 13. A hearth as inclaim 11 wherein said heat shield is a one-piece heat shield.
 14. Afreestanding fireplace hearth having a bottom, a plurality of sides, aroof, a snuffer and a movable fuel tray mounted operably beneath saidsnuffer and being movable laterally for fueling, said tray movableupwardly for sealing engagement with said snuffer when disposedthereunder and movable downwardly away from said snuffer when pulledlaterally for refueling, said hearth further having a plurality of postsdefining corners, each post having an elongated slot therein forreceiving and holding an edge of a glass side of said hearth, and saidelongated slot having an elongated groove therein for receiving a tenonof a structural side member therein above said glass side.
 15. A hearthas in claim 14 further including a roof panel and a roof-mounted heatshield mounted to said roof, and further including mounting projectionson said heat shield, said projections being receivable in open ends ofsaid posts.
 16. A free-standing fireplace hearth for burning a fuel toprovide ambiance fire, the system comprising: a base having a drawerslidably mounted therein for movement between open and closedconfigurations; a spring biased latch to releasably secure the drawer inthe closed configuration; a tray moveably mounted in the drawer andadapted to receive therein the fuel, the tray being mounted for movementbetween a lowered and a raised position; a plurality of links pivotallycoupled at a first end to the drawer and pivotally coupled at a secondend to the tray; a stop mounted on the base relative to the drawer andthe tray so that as the drawer approaches the closed configuration thetray abuts against the stop and continued movement of the drawer towardthe closed configuration pivots the links and thereby elevates the trayrelative to the drawer into the raised position and sealing contact witha flue; a pair of spaced damper shutters mounted for movement to andbetween a closed snuffing configuration and a fully open configuration,each of the damper shutters being coupled via a linkage to a rotationalcontrol knob such that rotation of the control knob in a first directionpivots the damper shutters toward the closed snuffing configuration andsealing contact with the tray and the flue to extinguish the burningfuel and rotation of the control knob in a second direction pivots thedamper shutters toward the fully open configuration to allow increasingamounts of air to the burning fuel; a plurality of posts extendingupwardly from the base; a cover supported by the posts; a heat shieldmounted interiorly of the cover to deflect hot air generated by theburning fuel from impinging upon the cover and maintain the cover at alower temperature than the heat shield during fuel burning, at least aportion of the heat shield being spaced from the cover to permit aninsulation layer of air between the heat shield and the cover; and aplurality of baffles in the heat shield to direct the hot air from theheat shield and cooler air into the insulation layer of air between thecover and the heat shield.
 17. A fireplace hearth comprising: alaterally movable fuel tray defining a volatile fuel chamber, aconstricting throat in said fuel tray above said chamber; a snuffer;said tray being operably oriented beneath said snuffer; a wedge-shapeddiverter in an upper portion of said snuffer and defining two openings;an adjustable damper movable toward and away from each said opening toadjust the size of said openings in a plurality of flame burningpositions and to close off each respective opening; a log set disposedabove said snuffer, said log set having a plurality of flame passagestherethrough for receiving flame from openings in said snuffer and forreceiving air from outside said snuffer, said air mixing with andlifting said flame through said log set.
 18. A hearth as in claim 17wherein said log set, when heated by said flame, causes convection ofair through said flame passages.
 19. A hearth as in claim 18 whereinsaid dampers are movable to reduce the size of said openings and therebythe flame and amount of heat produced by said flame, said dampersthereby reducing the flow of convection air through said log set.
 20. Ahearth as in claim 17 wherein said tray is movable downwardly andlaterally out from under said snuffer for filling with fuel, and thenlaterally under and operably upwardly toward said snuffer for burning ofsaid fuel.
 21. A crackling gel fuel comprising a fuel source, a gellingagent and encapsulated solvents said encapsulated solvent having a sizeand composition effective to maximize crackling sound when burned.
 22. Awater soluble fuel composition providing a golden flame and generating acrackling sound without excessive smoke comprising: a flammable loweralkyl alcohol; a flammable non-aromatic organic compound effective toproduce a golden flame during combustion; microcapsules containing aflammable organic solvent different from said non-aromatic organiccompound and said lower alkyl alcohol.
 23. A water soluble fuelcomposition which, when burned, provides a golden flame and a cracklingsound without excessive smoke comprising: a flammable lower alkylalcohol in an amount effective to enable said fuel to maintain aself-contained flame; a flammable non-aromatic organic solvent effectiveto produce a golden flame, said solvent selected from the groupconsisting of aliphatic hydrocarbons and yellow burning alcohols andmixtures thereof; water soluble gelling agent comprising a polyacrylicacid and water; and microcapsules of an aromatic solvent.
 24. The fuelcomposition as in claim 23 wherein said lower alkyl alcohol is ethanol.25. The-fuel composition as in claim 24 wherein said aliphatichydrocarbon has an aniline point of at least about 180 degrees F. 26.The fuel composition as in claim 25 further comprising tertiary butylalcohol.
 27. A fuel composition comprising: 50% to 65% by weightethanol; 2% to 15% by weight aliphatic hydrocarbon having an anilinepoint about 180 degrees F.; 0 to 12% tertiary butyl alcohol; an amountof microencapsulated flammable aromatic compound effective to cause acrackly sound when burned; and a gel composition comprising water and apolyacrylic acid or salt thereof in amounts effective to establish aviscosity effective to suspend said microencapsulated flammable aromaticcompound.
 28. The fuel composition as in claim 27 comprising at leastabout 2% tertiary butyl alcohol.
 29. The fuel composition as in claim 27wherein said gel comprises 0.2-1.2% polyacrylic acid and 25-33% byweight water base on the weight of said fuel.
 30. The fuel compositionas in claim 28 wherein said microcapsules contain an aromatic solventhaving a vapor pressure of 5 to 15 mm Hg at 68 degrees F. and a boilingrange of 300-325 degrees F.